Milford Cubicle II, in all the time I've been doing this work, I've heard people compare batteries in a lot of different ways, typically starting with price and warranty (neither of which you've mentioned). I've never heard anyone compare batteries by volume. To be honest with you, because of the Spiralcell design of our batteries, I wouldn't even know how to accurately calculate the volume of our batteries without asking one of our engineers. I do know the volume you cited for our battery, by simply multiplying the length, width and height, is overstated, as those dimensions indicate the maximum space occupied by the battery and do not reflect the actual volume of the battery itself.
If you want to compare our Group 27 battery with anyone else's, an accurate comparison is with another Group 27 battery. The BCI came up with universal specifications to allow consumers to make an apples to apples comparison. If you want to dissect those numbers further, by comparing reserve capacity per pound, cranking amps per pound or even price per pound, you are welcome to do that.
I am glad to hear you learned from your mistake of purchasing a used battery with an unknown service history. I haven't bought a used vehicle since 1990, simply because I got tired of dealing with issues created and/or ignored by previous owners. I don't buy second-hand tires, used batteries or any other second-hand products for my vehicles that have a finite life cycle and can potentially leave me stranded if they fail. While I understand the risk and reward is different for everyone, it just isn't worth the hassle for me.
Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
www.facebook.com/optimabatteries